A known valve timing control apparatus controls opening timing and closing timing of intake valves or exhaust valves by changing a rotational phase between a crankshaft and a camshaft of an internal combustion engine installed in, for example, a vehicle.
JP2009-515090A (corresponding to US2007/0095315A1) recites a valve timing control apparatus that includes a hydraulic pressure control valve, which is installed in a vane rotor that is rotatable relative to a housing. More specifically, the hydraulic pressure control valve is installed in a center hole of the vane rotor, which extends in a direction of a rotational axis of the vane rotor. The hydraulic pressure control valve shifts from one oil passage to another oil passage to supply the oil, which is received from an oil pump, to advancing chambers or retarding chambers formed in the housing. In this way, the valve timing control apparatus can advance or retard the vane rotor relative to the housing.
However, the hydraulic pressure control valve of JP2009-515090A (corresponding to US2007/0095315A1) has an output port at a location that is projected from the center hole of the vane rotor to the outside of the housing. Therefore, in the hydraulic pressure control valve, the oil of the retarding chambers is discharged from the output port to the outside of the housing at the time of supplying the oil to the advancing chambers. Also, the oil of the advancing chambers is discharged from the output port to the outside of the housing at the time of supplying the oil to the retarding chambers. Therefore, it is difficult to use a drive belt, such as a toothed belt, a flat belt or a V-belt, in a drive force transmission mechanism located between the crankshaft of the engine and the housing in the valve timing control apparatus.